I have done the upgrade to the beta on a MacBook pro and new iMac, so far with good results.
However, on 2 Mac Pros we have (newest model), the VMs are installed on a Raid 0 drive (2 1TB drives concatenated).
When starting one VM while another is running, the system goes 'black' and reboots. No 'documented' kernel panic, so the console log has no time to write much about the cause.
Thx,
dan ...